| Cooperation and Coordination Between Fuzzy Reinforcement Learning Agents in Continuous State Partially Observable Markov Decision Processes - Berenji, Hamid R. Successful operations of future multi-agent intelligent systems require efficient cooperation schemes between agents sharing learning experiences. We consider a pseudo-realistic world in which one or more opportunities appear and disappear in random locations. Agents use fuzzy reinforcement learning to learn which opportunities are most worthy of pursuing based on their promise rewards, expected lifetimes, path lengths and expected path costs... Keywords: LIBRATION; INTERFEROMETRY; LINEAR QUADRATIC REGULATOR; RESEARCH; ORBIT DETERMINATION; FLIGHT CHARACTERISTICS; ALGORITHMS; KALMAN FILTERS; LINEARIZATION; OPTICAL MEASUREMENT Downloads: 60 | |

| High Temperature Polyimide Materials in Extreme Temperature Environments - Johnson, Theodore F. At the end of the NASA High Speed Research (HSR) Program, NASA Langley Research Center (LaRC) began a program to screen the high-temperature Polymeric Composite Materials (PMCs) characterized by the HSR Durability Program for possible use in Reusable Launch Vehicles (RLVs) operating under extreme temperature conditions. The HSR Program focused on developing material-related technologies to enable a High Speed Civil Transport (HSCT) capable of operating temperatures ranging from 54 C (-65 F) to 1... Keywords: SPACECRAFT MANEUVERS; DIFFERENTIAL EQUATIONS; LINEAR QUADRATIC REGULATOR; CONTROLLABILITY; SATELLITE OBSERVATION; CONTROLLERS; WEIGHT REDUCTION; PLANAR STRUCTURES; TRAJECTORIES; REMOTE SENSING Downloads: 94 | |

| Minimal parameter solution of the orthogonal matrix differential equation - Bar-Itzhack, Itzhack Y. As demonstrated in this work, all orthogonal matrices solve a first order differential equation. The straightforward solution of this equation requires n sup 2 integrations to obtain the element of the nth order matrix. There are, however, only n(n-1)/2 independent parameters which determine an orthogonal matrix. The questions of choosing them, finding their differential equation and expressing the orthogonal matrix in terms of these parameters are considered... Keywords: AIRCRAFT CONTROL; FLIGHT PATHS; MICROBURSTS (METEOROLOGY); WIND SHEAR; LINEAR QUADRATIC REGULATOR; THRUST; WIND DIRECTION; WIND EFFECTS; WIND VELOCITY Downloads: 142 | |

| SRM Internal Flow Tests and Computational Fluid Dynamic Analysis - NON This document presents the full-scale analyses of the CFD RSRM. The RSRM model was developed with a 20 second burn time. The following are presented as part of the full-scale analyses: (1) RSRM embedded inclusion analysis; (2) RSRM igniter nozzle design analysis; (3) Nozzle Joint 4 erosion anomaly; (4) RSRM full motor port slag accumulation analysis; (5) RSRM motor analysis of two-phase flow in the aft segment/submerged nozzle region; (6) Completion of 3-D Analysis of the hot air nozzle manifold... Keywords: AUTOMATIC CONTROL; LINEAR QUADRATIC REGULATOR; AUTONOMY; FEEDBACK CONTROL; GRAVITATIONAL EFFECTS; ALGORITHMS; EARTH OBSERVING SYSTEM (EOS); TRANSFER ORBITS; MATRICES (MATHEMATICS); LINEARIZATION Downloads: 176 | |

| The High Energy Solar Physics mission (HESP): Scientific objectives and technical description - Crannell, Carol The High Energy Solar Physics mission offers the opportunity for major breakthroughs in the understanding of the fundamental energy release and particle acceleration processes at the core of the solar flare problem. The following subject areas are covered: the scientific objectives of HESP; what we can expect from the HESP observations; the high energy imaging spectrometer (HEISPEC); the HESP spacecraft; and budget and schedule. Keywords: CONTROL STABILITY; LINEARIZATION; ROBOT CONTROL; SPACE SHUTTLE PAYLOADS; CONTROL SYSTEMS DESIGN; CONTROL THEORY; DYNAMIC STABILITY; LINEAR QUADRATIC REGULATOR; OPTIMAL CONTROL; REMOTE MANIPULATOR SYSTEM; VIBRATION DAMPING; EQUATIONS OF MOTION Downloads: 143 | |

| ICAN sensitivity analysis - Frimpong, Stephen A computer program called Integrated Composite Analyzer (ICAN) was used to predict the properties of high-temperature polymer matrix composites. ICAN is a collection of NASA Lewis Research Center-developed computer codes designed to carry out analysis of multilayered fiber composites. The material properties used as input to the program were those of the thermoset polyimide resin PMR-15 and the carbon fiber Celion 6000... Keywords: CONTROL SYSTEMS DESIGN; DIFFERENCE EQUATIONS; MATRICES (MATHEMATICS); MEAN SQUARE VALUES; MULTIPLIERS; OPTIMIZATION; CONTROLLERS; LINEAR QUADRATIC REGULATOR; OPTIMAL CONTROL; RANDOM SAMPLING; SAMPLED DATA SYSTEMS; STABILITY; STOCHASTIC PROCESSES; COMPUTERIZED SIMULATION Downloads: 65 | |

| Support system for a 1750A VHSIC multiprocessor - Ruggles, Stephen L A design approach for a support system or test station necessary to functionally operate a very high-speed integrated circuit (VHSIC) microprocessor brassboard is presented. Major subsystems which make up the support are the following: (1) power supply unit; (2) temperature controller unit; (3) input/output module; and (4) mechanical test fixture. Theoretical analyses and experimental techniques were utilized to design and implement the power and temperature requirements for the VHSIC processor... Keywords: CONTROL STABILITY; LINEAR QUADRATIC REGULATOR; RICCATI EQUATION; SYSTEMS STABILITY; DISTRIBUTED PARAMETER SYSTEMS; FEEDBACK CONTROL; HILBERT SPACE; LIAPUNOV FUNCTIONS; LINEAR SYSTEMS; OPERATORS (MATHEMATICS); CONTROL THEORY; DECOMPOSITION Downloads: 82 | |

| Effect of grain size on the high temperature properties of B2 aluminides - Whittenberger, J. Danie Measurements of the slow plastic flow behavior of cobalt, iron and nickel B2 crystal structure aluminides were conducted on materials fabricated by metallurical techniques. Due to this processing, the aluminides invariably had small equiaxed grains, ranging in size from about 3 to 60 microns in diameter. Grain size was dependent on the extrusion temperature used for powder consolidation, and it proved to be remarkably stable at elevated temperatures... Keywords: APPROXIMATION; FEEDBACK CONTROL; LINEAR QUADRATIC REGULATOR; STATE ESTIMATION; COMPENSATORS; CONTROL SYSTEMS DESIGN; FLEXIBLE BODIES; LINEAR QUADRATIC GAUSSIAN CONTROL; RICCATI EQUATION; CONVERGENCE; DYNAMIC CONTROL; ESTIMATORS Downloads: 48 | |

| MIT 6.832 Underactuated Robotics, Spring 2009 - MIT OpenCourseWare Instructor: Russell Tedrake Robots today move far too conservatively, using control systems that attempt to maintain full control authority at all times. Humans and animals move much more aggressively by routinely executing motions which involve a loss of instantaneous control authority. Controlling nonlinear systems without complete control authority requires methods that can reason about and exploit the natural dynamics of our machines... Keywords: underactuated robotics; actuated systems; nonlinear dynamics; simple pendulum; optimal control; double integrator; quadratic regulator; Hamilton-Jacobi-Bellman sufficiency; minimum time control; acrobot; cart-pole; partial feedback linearization; energy shaping; policy search; open-loop optimal control; trajectory stabilization; iterative linear quadratic regulator; differential dynamic programming; walking models; rimless wheel; compass gait; kneed compass gait; feedback control; running models; spring-loaded inverted pendulum; Raibert hoppers; motion planning; randomized motion planning; rapidly-exploring randomized trees; probabilistic road maps; feedback motion planning; planning with funnels; linear quadratic regulator; function approximation; state distribution dynamics; state estimation; stochastic optimal control; aircraft; swimming; flapping flight; randomized policy gradient; model-free value methods; temporarl difference learning; Q-learning; actor-critic methods Downloads: 18,532 | |

| Strength, Fracture Toughness, and Slow Crack Growth of Zirconia/Alumina Composites at Elevated Temperature - Choi, Sung R. Various electrolyte materials for solid oxide fuel cells were fabricated by hot pressing 10 mol yttria-stabilized zirconia (10-YSZ) reinforced with two different forms of alumina particulates and platelets each containing 0 to 30 mol alumina. Flexure strength and fracture toughness of platelet composites were determined as a function of alumina content at 1000 C in air and compared with those of particulate composites determined previously... Keywords: NANOSATELLITES; GLOBAL POSITIONING SYSTEM; LINEAR QUADRATIC REGULATOR; COMPUTERIZED SIMULATION; ORBITAL MECHANICS; SATELLITE DESIGN; ACTUATORS; PULSED PLASMA THRUSTERS; KEPLER LAWS; SATELLITE ATTITUDE CONTROL; TRAJECTORY CONTROL; SYSTEMS INTEGRATION; CONTROL SYSTEMS DESIGN; ORBIT DETERMINATION; CONTROL SIMULATION; EQUATIONS OF MOTION; SATELLITE ORBITS Downloads: 98 | |

| Acoustic Aspects of Active-Twist Rotor Control - Booth, Earl R., Jr. The use of an Active Twist Rotor system to provide both vibration reduction and performance enhancement has been explored in recent analytical and experimental studies. Effects of active-twist control on rotor noise, however, had not been determined. During a recent wind tunnel test of an active-twist rotor system, a set of acoustic measurements were obtained to assess the effects of active-twist control on noise produced by the rotor, especially blade-vortex interaction (BVI) noise... Keywords: REUSABLE LAUNCH VEHICLES; X-33 REUSABLE LAUNCH VEHICLE; AEROSPACE SAFETY; MONTE CARLO METHOD; SPACECRAFT RELIABILITY; FLIGHT SIMULATION; LINEAR QUADRATIC REGULATOR; FLIGHT CONTROL; FLIGHT TESTS; ENTRY GUIDANCE (STS); CONTROL SYSTEMS DESIGN; METHODOLOGY; COST REDUCTION; ALGORITHMS; ASCENT Downloads: 78 | |

| Flightweight Carbon Nanotube Magnet Technology - Chapman, J. N. Virtually all plasma-based systems for advanced airborne/spaceborne propulsion and power depend upon the future availability of flightweight magnet technology. Unfortunately, current technology for resistive and superconducting magnets yields system weights that tend to counteract the performance advantages normally associated with advanced plasma-based concepts. The ongoing nanotechnology revolution and the continuing development of carbon nanotubes (CNT), however, may ultimately relieve this l... Keywords: SPACECRAFT CONTROL; VECTORS (MATHEMATICS); ENERGY STORAGE; KINETIC ENERGY; INTERNATIONAL SPACE STATION; SPACECRAFT MANEUVERS; LINEAR QUADRATIC REGULATOR; ANGULAR MOMENTUM; ATTITUDE CONTROL; CONTROL MOMENT GYROSCOPES; FLYWHEELS; CONTROL SYSTEMS DESIGN; CONTROL SIMULATION; CONTROL THEORY; EQUATIONS OF MOTION; NONLINEAR EQUATIONS Downloads: 130 | |